In this paper, we try to show that it is not possible to ascribe, unambiguously, the label "anti-scientific" to a set of ideas. Anti-science is a description applicable to certain human activities; it is not a quality of certain ideas. We will illustrate this by looking at the case of parapsychological ideas (1). This approach implies that we do not endorse any positive definition of anti- science within this paper. The argument is intended to show the inappropriateness of definitions that would identify anti-science with sets of ideas as opposed to sets of historically specific actions. We will, however, look at some of the reasons that are given when ideas are so labelled, and we will put forward suggestions as to why actors should be interested in applying the label in this way to parapsychological ideas.